1. Field of the Invention
The present invention relates to a system and method for controlling operation of semiconductor equipment. More particularly, this invention relates to a system and method of using semiconductor equipment to verify the contents of a process recipe and perform a semiconductor device manufacturing process using an appropriate recipe.
2. Description of Related Art
Generally, a semiconductor device manufacturing method includes a deposition process in which a material layer is formed on a semiconductor substrate, a photolithography process in which a mask layer is formed on the material layer and the mask layer is patterned to form a mask pattern, an etching process in which the material layer is etched using the mask pattern as an etching mask, an ion implantation process in which impurity ions are implanted using the mask pattern as an ion implantation mask, various annealing processes, and other processes. To generate a high manufacturing yield, these processes should be precisely managed and controlled according to a predetermined sequence using a semiconductor equipment control system.
Most of these processes are controlled with respect to a single cassette in which a plurality of wafers in a single lot is mounted. For example, in a dry etching process using plasma, a cassette containing a lot of about twenty-five wafers is loaded into a load port of the semiconductor equipment to perform the dry etching process. The semiconductor equipment control system then reads a process program identification (ID) from the cassette loaded in the load port and searches for a corresponding process recipe (e.g., conditions for performing the process) pre-stored in the semiconductor equipment. The semiconductor equipment then performs the process according to the process recipe.
FIG. 1 is a flowchart illustrating a conventional semiconductor equipment control method. Referring to FIG. 1, after loading a wafer lot (typically consisting of about 25 wafers) into the load port of the semiconductor equipment and searching for the process recipe corresponding to the lot, a host installed in the semiconductor equipment control system checks the entire recipe body of the searched process recipe (S10). Unfortunately, since the recipe body of the process recipe includes numerous specific conditions for performing a process (including, for example, a process environment, a process sequence, and a process type), it may take as long as ten minutes or longer to check the recipe body. To check the recipe body of the process recipe, the host compares values of the checked process recipe contents with the contents of a reference recipe (e.g., conditions appropriate to perform a process) stored in the host and then, determines whether the values of the checked process recipe are within an allowable tolerance range with respect to the reference recipe values (S30).
When the values of the checked process recipe are within the allowable tolerance range with respect to the reference recipe values, the host transmits a predetermined control signal to the semiconductor equipment to allow the semiconductor equipment to perform a process according to the checked process recipe (S70). When the values of the checked process recipe are not within tolerance of the reference recipe, however, the host transmits an interlock signal to the semiconductor equipment to keep the semiconductor equipment from performing a process according to the process recipe (S50).
Unfortunately, since the host searches for a process recipe and checks the recipe body of the process recipe whenever the lot is loaded in the semiconductor equipment, regardless of whether the process recipe has been modified, this unconditional checking procedure results in an unnecessary loss of process time. In particular, where the values of the pre-checked process recipes stored in the semiconductor equipment are within tolerance of the reference recipe, since most process recipes are not modified until they correspond to a subsequent lot, the conventional method of unconditionally checking the recipe body of every process recipe results in unnecessary delay and a corresponding decrease in productivity.
The industry would therefore benefit from a system and method for controlling semiconductor equipment that result in increased productivity by reducing or eliminating the unnecessary delay associated with conventional unconditional recipe checking.